This invention relates to a disc player having a centering mechanism which, in inserting a disc into the disc inserting opening thereof, operates to position the disc at the center of the disc inserting opening.
Recently, a compact disc has been developed which has a recording layer having pits corresponding to digital signals obtained by converting analog sounds (hereinafter referred merely as "a disc", when applicable). With the disc, analog sounds are optically reproduced by using a laser beam applied by the reading head of a CD (compact disc) player. The disc is much superior both in tone quality and in operability to conventional LP record discs. Hence, the compact disc together with its CD player has quickly come into wide use. Accordingly, CD players to be mounted on vehicles have been developed (hereinafter referred to as "vehicle disc players", when applicable). One example of the vehicle disc players is as shown in FIG. 1. In FIG. 1, reference numeral 101 designates a disc of 12 cm in diameter in which pieces of music have been recorded. When the disc 101 is inserted into a disc inserting opening 102, it is conveyed to a predetermined position (which is substantially the center of the CD player) by a loading mechanism 103, where it is fixedly mounted on the turntable 105 by a clamper arm 104. The disc 101 thus mounted is rotated by a spindle motor (not shown), so that the pieces of music are reproduced with a reading head (not shown). In the vehicle CD player, the clamper arm 104, the turntable, and the reading head are supported in floating manner so that they are substantially free from vibration during traveling.
On the other hand, a disc 106 of 8 cm in diameter, which is much smaller in diameter than the disc 101 of 12 cm in diameter, has been proposed in the art.
The above-described conventional vehicle CD player suffers from the following difficulties: It is rather difficult to insert a disc into the disc inserting opening 102 at the middle, and therefore it is necessary to use the centering mechanism. Particularly it is difficult to insert the 8 cm disc into the disc inserting opening 102 at the middle, because the disc inserting opening 102 is large. If, in inserting the disc into the opening 102, it is shifted from the middle of the opening 102, then it is impossible to set the disc at the predetermined position on the turntable. In particular, in an automotive CD player, since the player is vibrated during a travel of the vehicle, it is more difficult to insert a small disc into the disc inserting opening.
This difficulty may be eliminated by provision of the centering mechanism which move the disc to the middle of the disc inserting opening if it is shifted therefrom. That is, the centering mechanism has a centering pin which, when a disc is inserted into the disc inserting opening, limits the shifting of the disc from the middle of the opening. The centering pin, located near the disc inserting opening, may result in the following difficulty: In the case where a 12 cm large disc 101 is mounted on the turntable 105, the centering pin and the disc 101 ma collide with each other by vibration of the vehicle traveling, since the turntable is floatingly supported to the base.